Cable safety fence with noise absorbing panel

ABSTRACT

A cable road safety fence for installation at a lateral or median side of a road has a series of spaced apart upright posts, and a plurality of tensioned cables provided at different levels on and supported by said posts. At least one noise absorbing panel is mounted onto the cables with at least two mounting points, said points being at different levels.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national stage of PCT/EP2019/050200 filed Jan. 7, 2019, which claims priority of European Patent Application 18150973.8 filed Jan. 10, 2018 both of which are hereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates to a cable road safety fence for installation at a lateral or median side of a road, said cable safety fence comprises a series of spaced apart upright posts, and a plurality of tensioned cables provided at different levels on and supported by said posts.

BACKGROUND OF THE INVENTION

It is well known to provide safety fences at the lateral side of a road with the object of limiting personal injuries by absorbing the energy of a vehicle veering off the road by catching and slowing down the vehicle. Different types of such safety fences are known. One type is a cable safety fence having a plurality of cables, typically 3 or 4 wire ropes or cables, which are tensioned horizontally between upright posts that are spaced a certain distance apart at the side of a road. The cables are thus essentially horizontally extending, i.e. being substantially parallel with the ground, and provided at different levels above the ground. Examples of such cable safety road fences are known from U.S. Pat. No. 5,039,066 or WO 2010/079334 A1.

Another type of road safety fences is the guard rail type. Such guard rail type safety fences may also be provided with noise absorbing means of various kinds, such as disclosed in WO 2010/018028 or EP 1 528 158 A1.

In order to ensure road safety and to reduce the risk of personal injuries it is required that a safety fence must be able to absorb the impact of a collision without disintegrating. This requirement is also applicable to the noise reducing means. This requirement is to avoid flying objects and/or sharp fractures which can cause severe personal injuries in case of a collision. In the guard rail type safety fences with noise-reducing measures mentioned above, the casing in aluminium or transparent materials, such as glass or plastic, are brittle, costly and may not withstand a vehicle impact without breaking apart. From PCT/EP2017/067073 (not yet published) and PCT/EP2017/067089 (not yet published) a guard rail with a noise absorbing panel attached is known.

Turning back to the road safety fences of the cable type it is not known to provide such road safety fences with noise reducing means.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a wire cable road safety fence with a noise reducing capability.

This object is achieved by a safety fence of the initially mentioned kind wherein at least one noise absorbing panel is mounted onto the cables with at least two mounting points at different levels.

By providing the noise absorbing panels attached to the cables, an extra mass is provided which will contribute to absorb the energy of a vehicle impact and thereby improve the road safety fence performance. In order to meet the safety requirements for road safety fences, it is hereby ensured that the noise absorbing panel will not break off the cable fence structure if impacted by a vehicle. In addition, by mounting the noise panel at mounting points at different levels it is prevented that the noise reducing panel can swing around one of the cables in the cable fence.

Advantageously, the noise absorbing panel comprises a noise absorbing material board which is encased in an energy absorbing material provided with openings. Such an energy absorbing material provided with openings can be formed by a mesh, a grid or a perforated material.

By the invention it is found advantageous that the noise absorbing panel is contained in an energy absorbing material, e.g. said mesh whereby an improved noise absorbing panel in a guard rail system may be achieved, which also meets the requirements concerning impact absorption and avoids disintegration at an impact with a vehicle.

The noise absorbing material is preferably a mineral wool fibre board, which has very good noise-absorbing characteristics. However, it is realised that the noise absorbing panels can also be made with other materials, like foam material, integrated or partial rubber material, integrated or partial plastic material, or other noise absorbing material resistant in regard to weather conditions and wear effects next to traffic ways.

Besides that the mineral wool fibre board, and more preferably a stone wool material, has very good noise-absorbing characteristics, another advantage by in particular stone wool as the material is that this material fire-resistant.

In the preferred embodiment of the invention, the energy absorbing material is a stretch metal netting encasing said noise absorbing material board. Stretch-metal or expanded metal provide very good energy-absorbing characteristics as the netting made of stretch-metal can be deformed to a large degree when impacted. Depending on the design of the stretch metal netting it is possible to provide different stretch behaviour in respective stress directions. For instance, it is possible to provide a higher stress resistance and thereby a higher energy absorption in an impact situation in longitudinal direction of the traffic way than in vertical direction. In those directions, where the stretch metal netting provides a higher stress resistance, the meshes of the stretch metal netting may provide a higher amount of deformation. In those directions where the stretch metal netting has less stress resistance, the meshes of the stretch metal netting deform less. This can be achieved e.g. by rhombus formed meshes, which have a longer diagonal in vertical direction and a shorter diagonal in the horizontal direction. Thereby, the ability of deformation of the rhombus formed meshes in horizontal direction is higher than in vertical direction. Breaking of the panels in any situation, in particular in a crash-situation, is to be avoided.

Moreover, in addition to the mechanical behaviour of the netting made of stretch-metal, in particular in a stress situation, such a material can also provide additional beneficial optical and/or mechanical effects. The stretch metal may provide a surface structure with different groups of surfaces which are intentionally oriented into a particular direction. Thereby, it is possible to achieve particular optical reflection effects such that impacting light from a vehicle is reflected in preferred directions by certain groups of surfaces of the net material, whereas the impacting light is being dispersed in other less preferred directions. Moreover, inclining the groups of surfaces in preferred directions may also support that particular objects colliding with the net material may slide along the surface of the material with less friction in certain preferred directions, whereas objects impacting from another direction experience higher friction.

As an alternative to the stretch metal netting, the energy absorbing material can be formed of perforated metal sheets, multi-slit metal sheets, plastic nets, fibre reinforced plastic or rubber material, etc.

The encasing of the noise absorbing material is preferably a panel which encloses at least the main sides and the top side of the noise absorbing material. Preferably, the encasing is made from stretch-metal netting panel which is bent into the box-like shape around the noise absorbing material board. Hereby, the noise absorbing panel is also provided with good energy absorbing properties in case of a vehicle collision.

Advantageously a plurality of noise absorbing panels is provided in succession wherein neighbouring noise absorbing panels are abutting each other. Hereby, an unbroken noise screen is provided with no caps in between the noise absorbing panels.

In a particularly advantageous embodiment, the abutting neighbouring noise absorbing panels are secured to each other. Hereby, the noise absorbing panels will assist each other in absorbing the energy of a vehicle colliding with the safety fence as the panel which is first hit by the vehicle is pushed forward into the next panel, etc. due to the direction of impact of the vehicle.

Preferably, the mounting points between the noise absorbing panel(s) and the cables are laterally off-set from the mounting points between the cables and the upright posts. This ensures that the noise absorbing panels stay together with the cables during a collision.

In an embodiment of the invention, the at least one noise absorbing panel comprises a first mineral wool fibre board and a second mineral wool fibre board each having an interior surface and an exterior surface such that the interior surfaces of said first and second boards abut each other and said boards are secured at the at least two cables. Hereby, the noise absorbing panels are firmly secured to the cables so safety fence structure is less likely to disintegrate. Moreover, another advantage is that the cables are protected from the environment, such as corrosion protected, by the noise absorbing panels. The first mineral wool fibre board and/or the second mineral wool fibre board may be provided with grooves for receiving and accommodating the cables.

In one embodiment, each of the first mineral wool fibre board and second mineral wool board may be secured independently to the cable. This is found advantageous as this embodiment provides the advantage that during maintenance, only one mineral wool board can be removed to inspect the cable without removing the other adjoining board

Alternatively, said boards are secured to each other around the at least two cables. The assembly of the noise absorbing panel around the cables may be by gluing and/or bolting the first mineral wool fibre board and the second mineral wool fibre board to each other, such as using through-going tension bolts.

In a preferred embodiment, the exterior surfaces of the first mineral wool fibre board and the second mineral wool fibre board are provided with a protective exterior energy absorbing cover, such as a perforated metal panel, a stretch-metal panel or the like. The protective cover, such as panels or plates on each side of the noise absorbing panel may be glued to the surfaces of the first and second mineral boards, respectively or bolted together with the bolting used for the assembly of the noise absorbing panel.

In another embodiment, the at least one noise absorbing panel is provided as a material surrounding the at least two cables enclosing said cables, and preferably provided with a protective outer energy absorbing cover. The noise absorbing panel may be moulded or otherwise formed on site around the cables by moulding or otherwise forming a mineral wool fibre mixture or other kinds of suitable materials.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention is described in more detail with reference to the drawings, in which:

FIG. 1 is a schematic perspective view of a cable road safety fence according to an embodiment of the invention;

FIG. 2 is a schematic side view of same;

FIGS. 3 and 4 are two schematic side views of different embodiments of a cable road safety fence according to an embodiment of the invention;

FIG. 5 is a schematic top view of a cable road safety fence according to an embodiment of the invention;

FIGS. 6 to 8 are schematic side views of three embodiments according to a second series of embodiments, and

FIG. 9 is a schematic side view of a further embodiment of a cable road safety fence according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIGS. 1 to 5, a cable road safety fence according to an embodiment of the invention is shown, which is installed at a lateral or median side of a road 10. The cable safety fence comprises a series of spaced apart upright posts 1 with a plurality of tensioned cables 2 provided at different levels on and supported by said posts 1. On the side facing away from the road 10, a number of noise absorbing panels 3 are mounted onto the cables 2 with mounting points 4 at different levels, such that each noise absorbing panel 3 is mounted to at least two cables 2. The mounting points 4 may be such that the noise absorbing panels 3 are loosely mounted to the cables 2.

In FIGS. 2, 3 and 4 different configurations of the positioning of the cables 2 on the posts 1 are shown. These figures illustrate that the cables 2 may all be on the road facing side of the safety fence or only some of the cables are on the road facing side. Although the illustrated embodiments show three cables 2 and that the noise absorbing panel 3 is mounted to all three cables, it is realised by the invention that it may suffice to mount the noise absorbing panels to two of the cables 2, and that the number of cables may be chosen under the circumstances when designing the cable road safety fence.

As shown in FIGS. 1 and 5, the mounting points 4 between the noise absorbing panels 3 and the cables 2 are laterally off-set along the cable direction from the cable mounting points 5 between the cables 2 and the upright posts 1.

Each noise absorbing panel 3 comprises a noise absorbing material which is encased in an energy absorbing material provided with openings. The noise absorbing material is a mineral wool fibre material preferably provided as a board, in particular a stone wool fibre board, foam material, integrated or partial rubber material, integrated or partial plastic material, or other noise absorbing material resistant in regard to weather conditions and wear effects next to traffic ways.

The energy absorbing material provided with openings comprises a mesh, a grid or a perforated material. In a preferred embodiment, the energy absorbing material is a stretch-metal netting encasing said noise absorbing material. This is advantageous as the stretch-metal is a ductile metal capable of absorbing energy while being plastically deformed, preferably being galvanised steel. Alternatively or in addition to the stretch-metal, the energy absorbing material may be a perforated metal sheet, a plastic netting or the like and/or a combination thereof, encasing said noise absorbing material. The encasing is preferably provided as a panel which encloses at least the main sides and the top side of the noise absorbing material.

As shown in FIGS. 1 and 5, the noise absorbing panels 3 are provided in succession along the cables 2 of the safety road fence such the neighbouring noise absorbing panels are abutting each other. In a preferred embodiment, the abutting neighbouring noise absorbing panels 3 are secured to each other by suitable connecting elements 6. This ensures that the noise absorbing panels 3 cooperate in absorbing the energy of a vehicle colliding with the road safety fence as the energy can be transferred from one noise absorbing panel to the next.

While—as shown in the FIGS. 1 to 5—the noise absorbing panels 3 are provided as prefabricated panels and then mounted to the cables 2, it is realised by the invention that the noise absorbing panels 3 may also be provided as shown in the FIGS. 6 to 9 showing a second series of embodiments of the invention.

According to the embodiments of FIGS. 6 to 8, the noise absorbing panel 3 comprises a first mineral wool fibre board 31 and a second mineral wool fibre board 32 each having an interior surface and an exterior surface such that the interior surfaces of said first and second boards 31, 32 are abutting each other. The boards 31, 32 are then secured to each other around at least two cables 2, preferably all the cables 2. Accordingly, the first mineral wool fibre board 31 and the second mineral wool fibre board 32 may be secured to each other by adhesion as indicated in FIG. 6 and/or bolted together, such as using through-going tension bolts as indicated in FIG. 7. As a supplement or an alternative to this, the boards 31, 32 may also be secured to each other around the cables 2 by mounting elements 41, as indicated in the FIGS. 6 and 7.

As indicated in FIG. 6, the first mineral wool fibre board 31 and second mineral wool board 32 may also be secured independently to the cable 2 by mounting elements 42.

As indicated in FIG. 8, both the boards 31, 32 may also be secured to the cables 2 independently, where the first board 31 is secured to the cables 2 by mounting elements 41 and the second board 32 is secured to the cables 2 by the mounting elements 41 a.

In order to facilitate a tight fit, the first mineral wool fibre board 31 and/or the second mineral wool fibre board 32 is/are provided with grooves thereby providing channels for receiving and accommodating the cables 2. This can ensure a relatively loose mounting of the noise absorbing panels around the cables whilst also providing a protective encasing of the cables from being exposed to the environment.

As shown in the FIGS. 6 to 8, the exterior surfaces of the first mineral wool fibre board 31 and the second mineral wool fibre board 32 are provided with a protective exterior energy absorbing cover 33. The cover 33 may be a perforated metal panel, a stretch-metal panel or the like. The covers 33 may be pre-applied to the mineral boards 31, 32, e.g. by adhesive. The covers may also be provided as separate sheets mounted to the mineral wool fibre boards 31, 32 when these are mounted around the cables. To protect the top of the noise absorbing panel a top cover 34 may also be provided. This top cover 34 may be made from a metal sheet material or a polymeric sheet material. The cover is preferably mounted to the protective side covers 33.

Lining bars 21 preferably of an elastic material, such as plastic, may be provided on the road facing surface of the noise absorbing panel as shown in FIG. 6. The lining bars 21 are preferably provided substantially parallel with the cables and extend in the direction of the road safety fence.

In FIG. 9 there is illustrated an embodiment, wherein the noise absorbing panel is provided as a mineral wool fibre material surrounding the cables 2 enclosing the cables 2, and preferably provided with a protective outer energy absorbing covers 33 on each side. In this embodiment, the noise absorbing panel may be moulded or otherwise formed on site around the cables 2 by moulding or otherwise forming a mineral wool fibre mixture, a foam material or other kinds of suitable materials. Hereby, the noise absorbing panel can be provided as a continuous body, such as a non-divided body extending in the cable direction.

Above the invention is described with reference to some currently preferred embodiment. However, it is realised that variants may be provided without departing from the scope of the invention as defined in the accompanying claims. 

1. A cable road safety fence for installation at a lateral or median side of a road, comprising: a series of spaced apart upright posts, and a plurality of tensioned cables provided at different levels on and supported by said posts; at least one noise absorbing panel mounted onto the cables with at least two mounting points, said mounting points being at different levels.
 2. The cable safety fence according to claim 1, wherein said noise absorbing panel comprises a noise absorbing material which is encased in an energy absorbing material provided with openings.
 3. The cable safety fence according to claim 2, wherein the noise absorbing material is a mineral wool fibre material preferably provided as a board, foam material, integrated or partial rubber material, integrated or partial plastic material, or other noise absorbing material resistant in regard to weather conditions and wear effects next to traffic ways.
 4. The cable safety fence according to claim 2, wherein said energy absorbing material provided with openings comprises a mesh, a grid or a perforated material.
 5. The cable safety fence according to claim 2, wherein the energy absorbing material is a stretch-metal netting encasing said noise absorbing material.
 6. The cable safety fence according to claim 5, wherein the stretch-metal is a ductile metal capable of absorbing energy while being plastically deformed, preferably being galvanised steel.
 7. The cable safety fence according to claim 2, wherein the energy absorbing material is a perforated metal sheet, a plastic netting or the like and/or a combination thereof, encasing said noise absorbing material.
 8. The cable safety fence according to claim 2, wherein the encasing is a panel which encloses at least the main sides and the top side of the noise absorbing material.
 9. The cable safety fence according to claim 2, wherein the encasing is made from stretch-metal netting panel which is bent into the box-like shape around the noise absorbing material board.
 10. The cable safety fence according to claim 1, wherein a plurality of noise absorbing panels is provided in succession wherein neighbouring noise absorbing panels are abutting each other.
 11. The cable safety fence according to claim 10, wherein the abutting neighbouring noise absorbing panels are secured to each other.
 12. The cable safety fence according to claim 1, wherein the mounting points between the noise absorbing panel(s) and the cables are laterally off-set from mounting points between the cables and the upright posts.
 13. The cable safety fence according to claim 1, wherein the at least one noise absorbing panel comprises a first mineral wool fibre board and a second mineral wool fibre board each having an interior surface and an exterior surface such that the interior surfaces of said first and second boards abut each other and said boards are secured at the at least two cables.
 14. The cable safety fence according to claim 13, wherein each of the first mineral wool fibre board and second mineral wool board is secured independently to the cable.
 15. The cable safety fence according to claim 13, wherein said boards are secured to each other around the at least two of the plurality of cables.
 16. The cable safety fence according to claim 13, wherein the first mineral wool fibre board and/or the second mineral wool fibre board is/are provided with grooves for receiving and accommodating the cables.
 17. The cable safety fence according to claim 13, wherein the first mineral wool fibre board and the second mineral wool fibre board are secured to each other by adhesion and/or bolted together, such as using through-going tension bolts.
 18. The cable safety fence according to claim 13, wherein the exterior surfaces of the first mineral wool fibre board and the second mineral wool fibre board are provided with a protective exterior energy absorbing cover, such as a perforated metal panel, a stretch-metal panel or the like.
 19. The cable safety fence according to claim 1, wherein the at least one noise absorbing panel is provided as a material surrounding at least two of the plurality of cables enclosing said cables, and preferably provided with a protective outer energy absorbing cover. 